I had a go at your game, but it seems to run quite slowly. Jumping in particular seems very slow. And the horizontal movement seems to increment as if it is grid based. Is that correct?
I really like the idea of the game and would love to play multiplayer, contact me on twitter @BackNowhere if you would like to set it up :)
Art style seems great as well. Just felt very slow and clunky to move. If you can get faster, more fluid movement, that will definitely make it more enjoyable IMO.
Great work and look forward to hearing from you :)